The statistical
properties of the two-component plasma of cosmic-ray electrons and positrons
measured by the AMS-02 experiment on the International Space Station and the
HESS array of imaging atmospheric Cherenkov telescopes are analyzed. Stationary
non-equilibrium distributions defining the relativistic electron-positron
plasma are derived semi-empirically by performing spectral fits to the flux
data and reconstructing the spectral number densities of the electronic and
positronic components in phase space. These distributions are relativistic
power-law densities with exponential cutoff, admitting an extensive entropy
variable and converging to the Maxwell-Boltzmann or Fermi-Dirac distributions
in the non-relativistic limit. Cosmic-ray electrons and positrons constitute a
classical (low-density high-temperature) plasma due to the low fugacity in the
quantized partition function. The positron fraction is assembled from the flux
densities inferred from least-squares fits to the electron and positron spectra
and is subjected to test by comparing with the AMS-02 flux ratio measured in
the GeV interval. The calculated positron fraction extends to TeV energies,
predicting a broad spectral peak at about 1 TeV followed by exponential decay.